Lead alloy and method of preparing the same



- .used in coating such in Patented May 30, 1939 LEAD ALLOY AND METHOD OF AME This application refers to metals an ticularly to an alloy com lead, and is a continua Serial No. 84,562, filed June 10, 1936.

application,

THE S s PATENT oFFici:

PREPARING Nettie M. Hurd Bullock, Orlando, Fla. No Drawing. Application January 5, 1937,

Serial No. 7 Claims.

clmore parposed mostly of treated tion in part of.my prior Certain metals are unsuited for many uses, due

to their susceptibility oxidation, tarnish, and under weather conditions are to be subjected to the el with liquids which corrode previously treated .by dip processes to coat th which'is less susceptible t to corrosion by acids, their general disintegration Many metals which ements or to contact them ordinarily are ping, or electrolytic em with another product, 0 the substances in connection with which'said metals are to be used. One of the more familiar processes to be though there are a various processes are thus used without a coating is usually extent, porous. Wher base metal is subjec which protection is shortened and its use etals -is galvanizing, alnumber of others. These objectionable, inasmuch as brittle and is, to "a great ever porosity occurs, the

ted to the substance from desired, and its life is thus fulness impaired.

Moreover, there are functional difliculties in applying coatings of many of these coatin ture which has a dete to be coated; a

steel, where the tem by subjection to high temperatures.

many of these coatings are crystallin nature; and as, a result, will not stand friction or pressure. It is often desirabl certain articles out of lead but due to t of the product and various types as a great gs require a high temperariorating efiect on the metal s, for instance, in the case of per of the steel .is injured Moreover, e in, their up under e to make he nature its porosity as well as its tendency to darken, this product is objectionable.

An object of this metal and a method for the productio metal, which will overcome many of vantages inherent in object is to produce a place of lead, in which the porosity. greatly reduced and which will befree rosion or tarnish, thu A still further obie in which the crystalli ible, and which will so as to be easily applied as and when so applied, will itself to said metal, .in such invention is to produce a n of such a the disad- A further be used in of lead is from cors maintaining its brilliance. ct is to provide a lead alloy nestructure is not discerni be very fluid when molten a coating for metals, fill pores and fasten a way as to make a known coatings. metal which may permanent and lasting coat. A still further ob- Ject is .to provide a co to all metals at low ating which may be applied temperatures and may be stroying or injuring the applied.

not being subject to oxid gredients are mixed in t stantly agitated, until the chemical re "66.67% of th (NaCl) and the-mass a Another object is to provide a metal from which many if not all of the poisonous characteristics of lead have been removedand which, ation, is safe foruse in childrens toys and in similar trinkets.

A still further object is to provide a method of preparing an alloy which may, by the addition or omission of minor steps in process, be suited for a variety of purposes.

With these and other objects which will be- 10 come apparent as the description proceeds, my invention consists in the product and method of producing the same hereinafter described. It will be appreciated that both the product and the metal may and can be varie fit the product to particular uses and to give it certain desired characteristics and qualities.

In preparing my product, I mix a quantity of lead, preferably cut -in small pieces, nitric acid, sulphuric acid, and clay, or fullers earth, under 20 agitation. Of the entire mass by weight, the inhe following percentages or proportions:

This mass is allowed to work while being con- -action is complete. This takes about thirty (30) minutes. The entire mass is then heated, while being agitated, at about 700. at the top as a scum: This scum apparently consists of variousimpurities, contained in normal lead and this process-and the following steps remove such impurities and take with them their disadvantages. Thissc the molten metal tapped oiT from the bottom. The moltenfmetal represents by weight about e weight of the original ingredients; /3 of the weight of the ingredients either evapcrating or being left 'in the scum that forms at the top of the cauldron or retort;

Further refinement of the metal thusproduced may beaccomplished by the use of one or more of the following steps and the metal is kept "at 700 of the metal, about .054 part sodium chloride gitated until a scum forms, which scum is then removed, and to the remaining metal, about.67 part sodium silicate (NazSlOs) are added. Again sc d in slight detail to 15 F. until a residue forms 5 umis then skimmed oil or 40 still under agitation. To about-91.427 parts 60,

um forms and is removed L sists corrosion. While I 2 or the molten metal tapped off. About .107 part oxalic acid (H2C2O4) is then added, and the process repeated, still under agitation. Bismuth to the extent of about .861 part and 6.880 parts of tin are then added to the molten mass and agitated until thoroughly mixed.

The molten mass may be cast into pigs or ii to be used for dipping, passed into dipping tanks. Further refinement of the metal may be produced by adding copper acetate, sodium carbonate, potassium hydroxide or acetic acid, in amounts varying from to 2 parts, as compared to the metal. The use of these products tends to further purify the metal and to better suit it for varying purposes. The use of copper acetate, for instance, tends to make the metal whiter, stronger and to make it considerably har'der. When sodium carbonate or potassium hydroxide is used. the metal is likewise made whiter and is more suitable for decorative purposes, such as castings and novelties.

- The metal thus produced is one in which the crystalline structure is not discernible and the porosity which exists in lead is, to a great extent, removed.

It may be applied to other metals by dipping or other suitable means at temperatures as low as 665 F. and it has been found that, when so applied to steel and other metals, it cannot be effectively removed by friction, heat or otherwise. Moreover the metal is flexible and has a brilliant appearance, being almost white in color. it will not tarnish when subjected to the elements and resists acids, alkalis, salt water, and other substances which normally produce corrosion or oxidation.

It may be applied as a coating for all sorts of metals and is so fluid when molten that nuts and bolts and similar apparatus-may be coated without effecting their fit. Obviously, while I have set forth many uses such as coatings, the manufacture of lead toys, lining for tanks, etc., many other uses are apparent such as plates for storage batteries, and in other uses where lead is desired. .In the case of storage batteries, the metal is not seriously afiected by sulphuric acid fumes. and plates made of this metal are much more durable.

While in this specification, I have discussed my process with reference to lead, it is equally suited to other metals and when applied to aluminum and copper, produces an alloy which strongly rehave indicated the series of steps which produces the finished product, the

latter steps may be eliminated and at the same time, the method will produce-an alloy of very lead with approximately 6% by fine structure and high degree of purity.

I claim:

1. A process of preparing an alloy which consists in mixing, under agitation a metal such as lead with approximately 6% by volume of nitric acid, approximately 3% by volume of sulphuric acid, and approximately 8% by volume of clay until the chemical reaction has substantially ceased. then heating the mixture until thoroughly molten under agitation and until a scum forms, and then separating the scum from the metal. 1

2. A process of preparing an alloy which consists in mixing, under agitation, a metal such as volume of nitric acid, approximately 3% by volume of sulphuric acid and approximately- 8% by volume or clay until the chemical reaction has substantially ceased, thenheating themixture until thorough- -bismuth and approximately 8% chemical reaction heating the mixture under agitation until thor- 1y molten under agitation and until a scum forms, and then separating the scum from the metal, adding under agitation approximately & of 1% by volume of sodium chloride, removing the resultant scum and adding approximately twothirds of 1% by volume of sodium silicate, under agitation and again removing the resultant scum.

3. A process of preparing an alloy which consists in mixing, under agitation, a metal such as lead with approximately 6% by volume of nitric acid, approximately 3% by volume of sulphuric acid, and approximately 8% by volume of clay until the chemical reaction has substantially ceased, then heating the mixture until thorough- 1y molten under agitation and until a scum forms, and then separating the scum from the metal, adding approximately one-quarter of 1% by volume of oxalic acid and removing the resultant scum.

4. A process of preparing an alloy which consists in mixing, under agitation, a metal such as lead with approximately 6% by volume of nitric acid, approximately 3% by volume of sulphuric acid,'and approximately 8% byvolu'me .of clay until the chemical reaction has substantially ceased, then heating the mixture until thoroughly molten under agitation and until a scum forms, and then separating the scum from the metal, adding thereto approximately 1% by volume of by volume of tin.

5. A method of preparing an alloy which consists in treating approximately 86 parts of a metal such as lead with 6 parts of nitric acid and approximately 3 parts'of sulphuric acid in the presence of about 8 parts of fullers earth, agitating the same until'the chemical reaction is substantially diminished, at about 700 F. until a scum forms, ing said scum.

6. A method of preparing an alloy which conand remov- .sists in mixing under agitation a metal such as lead with approximately 6% by volume of nitric acid and approximately 3% phuric acid clay, until the chemical reaction has substantially ceased and heating the mixture until thoroughly molten and until a scum forms, separating the scum from the metal and adding under agitation approximately /0% by volume of sodium chloride, removing the resultant scum, and then adding approximately two-thirds of 1% by volume of sodium silicate, again removing the resulting scum, treating the remaining metal with approximately one-quarter of -1% by volume of oxalic acid and again removing thescum, and then adding thereto approximately 1% of bismuth and 8% of tin.

7. A process of preparing an alloy which consists in. mixing under agitation a metal such aslead with approximately 6% by volume of nitric acid, 3% by volume of sulphuric acid, and approximately 8% by volume of fullers earth until has substantially ceased, then oughly molten and until a scum forms, removing the scum from the metal and adding of 1% by volumeof sodium chloride, again agitating the mixture and removing the scum, then adding approximately two-thirds of 1% of sodium. silicate, agitating the metal, removing the resulting scum, then adding approximately one quarter of 1% oxalic acid, reagitatihg, and again removing the resulting scum and adding thereto approximately 1% or bismuth and 8% oftinl- NE'I'IIE M. HURD BULLOCK.

then' heating the mass by volume of suland approximately 8% by volume of 

